Conversion: Simulated Method of Exchanging Tourniquet Use for Pressure Dressing Use

John F Kragh Jr, James K Aden 3rd, Michael A Dubick

J Spec Oper Med. Fall 2020;20(3):44-51

Background: Given little data to assess guidelines, we sought a way to exchange one type of intervention, field tourniquet use, for another, use of a pressure dressing. The study purpose was to test performance of controlling simulated bleeding with a stepwise procedure of tourniquet conversion.

Methods: An experiment was designed to assess 15 tests of a caregiver making tourniquet-dressing conversions. Tests were divided into trials: tourniquet use and its conversion. In laboratory conditions, the tourniquet trial was care under gunfire; then, the conversion trial was emergency healthcare. A HapMed Leg Tourniquet Trainer simulated a limb amputation. An investigator provided healthcare.

Results: Mean (± standard deviation [SD]) test time and blood loss were 9 ± 3.6 minutes and 334 ± 353.9mL, respectively. The first test took 17 minutes. By test number, times decreased; the last six took ≤7 minutes. All tourniquet trials controlled bleeding. Mean (±SD) tourniquet pressure and blood loss were 222 ± 18.0mmHg and 146 ± 40.9mL, respectively. Bleeding remained uncontrolled in one conversion. Initial attempts to wrap a dressing were effective in 73% of tries (n = 11 of 15). Four of 15 wrap attempts (27%) were repeated to troubleshoot bleeding recurrence, and the first three tests required a repetition. Mean (±SD) dressing pressures and blood losses were 141 ± 17.6mmHg and 188 ± 327.4mL, respectively. Unsatisfactory conversion trials had a dressing pressure <137mmHg. Dressings and wraps hid the wound to impair assessment of bleeding.

Conclusions: In testing a method of converting a limb tourniquet to a pressure dressing, the caregiver performed faster with experience accrual. The tourniquet results were uniformly good, but conversion results were worse and more varied. Simulating conversion was disappointing on a manikin and indicated that its redesign might be needed to suit this method. The procedural method constituted a start for further development.